The present invention relates to an air-fuel ratio adaptive controlling apparatus for use in an internal combustion engine and, more particularly to an air-fuel ratio adaptive controlling apparatus for use in a gasoline internal combustion engine suitable for an automobile.
The present invention relates to an air-fuel ratio adaptive controlling apparatus for use in an internal combustion engine wherein an air-fuel mixture being supplied to the internal combustion engine is corrected or compensated during a transient period of an air-fuel ratio (A/F).
Fuel supplied from an injector is injected into an intake pipe of an internal combustion engine and is spread with an angle thereinto. Since the fuel is injected at a surrounding outer surface portion of an intake valve, a part of fuel adheres to the intake valve and an inner wall surface portion of the intake pipe. As a result, the fuel being sucked actually in a cylinder portion of the engine gets fewer. Thereby a misfire fire may occur during an acceleration operation of the engine and an operability of the engine may be damage.
An adhesion percentage or adhesion amount rate of an injected fuel with the intake valve and the intake pipe has a tendency to increase with a time passing change due to the adhesion of carbon or the like to the surrounding outer surface portion of the intake valve, therefore it is necessary to correct the fuel amount for compensating. However in the conventional internal combustion engine there are no considerations about the fuel supply compensation during time passing change caused by the fuel adhesion.
A conventional technique relating to the above mentioned fuel adhesion in an internal combustion engine discloses in, for example U.S. Pat. No. 4,388,906, in which a fuel supply amount compensation during a transient period such as a time at an acceleration operation of an engine is practised in accordance with an adhesion percentage or an adhesion amount rate of an injected fuel and an evaporation characteristic of an adhered fuel.
However, in the above mentioned conventional fuel adhesion technique there are no considerations about a concrete decision for an injected fuel adhesion percentage and an injected fuel adhesion percentage at a time passing change, thereby it gives rate to a problem that an airfuel ratio (A/F) correction at a transient period is not practised satisfactory.